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Berryhill BA, Burke KB, Smith AP, Morgan JS, Tarabay J, Mamora J, Varkey JB, Mumma JM, Kraft CS. A bacteriophage-based validation of a personal protective equipment doffing procedure to be used with high-consequence pathogens. Infect Control Hosp Epidemiol 2024:1-7. [PMID: 38706211 DOI: 10.1017/ice.2024.84] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2024]
Abstract
OBJECTIVE To determine if the high-level personal protective equipment used in the treatment of high-consequence infectious diseases is effective at stopping the spread of pathogens to healthcare personnel (HCP) while doffing. BACKGROUND Personal protective equipment (PPE) is fundamental to the safety of HCPs. HCPs treating patients with high-consequence infectious diseases use several layers of PPE, forming complex protective ensembles. With high-containment PPE, step-by-step procedures are often used for donning and doffing to minimize contamination risk to the HCP, but these procedures are rarely empirically validated and instead rely on following infection prevention best practices. METHODS A doffing protocol video for a high-containment PPE ensemble was evaluated to determine potential contamination pathways. These potential pathways were tested using fluorescence and genetically marked bacteriophages. RESULTS The experiments revealed existing protocols permit contamination pathways allowing for transmission of bacteriophages to HCPs. Updates to the doffing protocols were generated based on the discovered contamination pathways. This updated doffing protocol eliminated the movement of viable bacteriophages from the outside of the PPE to the skin of the HCP. CONCLUSIONS Our results illustrate the need for quantitative, scientific investigations of infection prevention practices, such as doffing PPE.
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Affiliation(s)
- Brandon A Berryhill
- Department of Biology, Emory University, Atlanta, GA, USA
- Program in Microbiology and Molecular Genetics (MMG), Graduate Division of Biological and Biomedical Sciences (GDBBS), Laney Graduate School, Emory University, Atlanta, GA, USA
| | - Kylie B Burke
- Department of Biology, Emory University, Atlanta, GA, USA
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA
| | - Andrew P Smith
- Department of Biology, Emory University, Atlanta, GA, USA
| | | | | | | | - Jay B Varkey
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA
- Emory Healthcare, Atlanta, GA, USA
| | - Joel M Mumma
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA
| | - Colleen S Kraft
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA
- Emory Healthcare, Atlanta, GA, USA
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA, USA
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2
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Vasseur L, Barbault F, Monari A. Interaction between Yersinia pestis Ail Outer Membrane Protein and the C-Terminal Domain of Human Vitronectin. J Phys Chem B 2024; 128:3929-3936. [PMID: 38619541 DOI: 10.1021/acs.jpcb.4c00965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
Yersinia pestis, the causative agent of plague, is capable of evading the human immune system response by recruiting the plasma circulating vitronectin proteins, which act as a shield and avoid its lysis. Vitronectin recruitment is mediated by its interaction with the bacterial transmembrane protein Ail, protruding from the Y. pestis outer membrane. By using all-atom long-scale molecular dynamic simulations of Ail embedded in a realistic model of the bacterial membrane, we have shown that vitronectin forms a stable complex, mediated by interactions between the disordered moieties of the two proteins. The main amino acids driving the complexation have also been evidenced, thus favoring the possible rational design of specific peptides which, by inhibiting vitronectin recruitment, could act as original antibacterial agents.
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Affiliation(s)
- Laurine Vasseur
- Université Paris Cité and CNRS, ITODYS, F-75006 Paris, France
| | | | - Antonio Monari
- Université Paris Cité and CNRS, ITODYS, F-75006 Paris, France
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3
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Kent JE, Ackermann BE, Debelouchina GT, Marassi FM. Dynamic Nuclear Polarization Illuminates Key Protein-Lipid Interactions in the Native Bacterial Cell Envelope. Biochemistry 2023; 62:2252-2256. [PMID: 37459255 PMCID: PMC11019665 DOI: 10.1021/acs.biochem.3c00262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/28/2023]
Abstract
Elucidating the structure and interactions of proteins in native environments is a fundamental goal of structural biology. Nuclear magnetic resonance (NMR) spectroscopy is well suited for this task but often suffers from low sensitivity, especially in complex biological settings. Here, we use a sensitivity-enhancement technique called dynamic nuclear polarization (DNP) to overcome this challenge. We apply DNP to capture the membrane interactions of the outer membrane protein Ail, a key component of the host invasion pathway of Yersinia pestis. We show that the DNP-enhanced NMR spectra of Ail in native bacterial cell envelopes are well resolved and enriched in correlations that are invisible in conventional solid-state NMR experiments. Furthermore, we demonstrate the ability of DNP to capture elusive interactions between the protein and the surrounding lipopolysaccharide layer. Our results support a model where the extracellular loop arginine residues remodel the membrane environment, a process that is crucial for host invasion and pathogenesis.
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Affiliation(s)
- James E Kent
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California 92037, United States
| | - Bryce E Ackermann
- Department Chemistry and Biochemistry, University of California San Diego, La Jolla, California 92093, United States
| | - Galia T Debelouchina
- Department Chemistry and Biochemistry, University of California San Diego, La Jolla, California 92093, United States
| | - Francesca M Marassi
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California 92037, United States
- Department of Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin 53226-3548, United States
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4
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Kolodziejek AM, Bearden SW, Maes S, Montenieri JM, Gage KL, Hovde CJ, Minnich SA. Yersinia pestis Δ ail Mutants Are Not Susceptible to Human Complement Bactericidal Activity in the Flea. Appl Environ Microbiol 2023; 89:e0124422. [PMID: 36744930 PMCID: PMC9973026 DOI: 10.1128/aem.01244-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 01/09/2023] [Indexed: 02/07/2023] Open
Abstract
Ail confers serum resistance in humans and is a critical virulence factor of Y. pestis, the causative agent of plague. Here, the contribution of Ail for Y. pestis survival in the flea vector was examined. Rat or human but not mouse sera were bactericidal against a Y. pestis Δail mutant at 28°C in vitro. Complement components deposited rapidly on the Y. pestis surface as measured by immunofluorescent microscopy. Ail reduced the amount of active C3b on the Y. pestis surface. Human sera retained bactericidal activity against a Y. pestis Δail mutant in the presence of mouse sera. However, in the flea vector, the serum protective properties of Ail were not required. Flea colonization studies using murine sera and Y. pestis KIM6+ wild type, a Δail mutant, and the Δail/ail+ control showed no differences in bacterial prevalence or numbers during the early stage of flea colonization. Similarly, flea studies with human blood showed Ail was not required for serum resistance. Finally, a variant of Ail (AilF100V E108_S109insS) from a human serum-sensitive Y. pestis subsp. microtus bv. Caucasica 1146 conferred resistance to human complement when expressed in the Y. pestis KIM6+ Δail mutant. This indicated that Ail activity was somehow blocked, most likely by lipooligosaccharide, in this serum sensitive strain. IMPORTANCE This work contributes to our understanding of how highly virulent Y. pestis evolved from its innocuous enteric predecessor. Among identified virulence factors is the attachment invasion locus protein, Ail, that is required to protect Y. pestis from serum complement in all mammals tested except mice. Murine sera is not bactericidal. In this study, we asked, is bactericidal sera from humans active in Y. pestis colonized fleas? We found it was not. The importance of this observation is that it identifies a protective niche for the growth of serum sensitive and nonsensitive Y. pestis strains.
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Affiliation(s)
- Anna M. Kolodziejek
- Department of Animal, Veterinary and Food Science, University of Idaho, Moscow, Idaho, USA
| | - Scott W. Bearden
- Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, Colorado, USA
| | - Sarah Maes
- Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, Colorado, USA
| | - John M. Montenieri
- Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, Colorado, USA
| | - Kenneth L. Gage
- Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, Colorado, USA
| | - Carolyn J. Hovde
- Department of Animal, Veterinary and Food Science, University of Idaho, Moscow, Idaho, USA
| | - Scott A. Minnich
- Department of Animal, Veterinary and Food Science, University of Idaho, Moscow, Idaho, USA
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Rhamnose-Positive Strains of Plague Agent: Virulence and Epidemiological Significance. PROBLEMS OF PARTICULARLY DANGEROUS INFECTIONS 2022. [DOI: 10.21055/0370-1069-2022-3-38-44] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The aim of the review is to show the groundlessness of the unconditional assessment of rhamnose-positive strains of plague pathogen as avirulent for most species of carriers and humans and having no epidemiological significance. The main carriers of rhamnose-positive strains are several species of voles and the Mongolian pika. The vast majority of experts are of the opinion that rhamnose-positive (“vole`s” and “pika`s”) strains of Yersinia pestis are avirulent or weakly virulent for many species of warm-blooded animals and humans, and therefore have no epidemiological significance. However, in a series of experiments on infecting marmots, ground squirrels, and large gerbils with rhamnose-positive strains, some of the experimental animals fell ill acutely and died from the plague. In nature, rhamnose-positive strains have been isolated from carcasses of relatively resistant red marmots. When evaluating the epidemiological significance of rhamnose-positive strains, such an important criterion as the presence or absence of effective factors and pathways of pathogen transmission in foci of the vole and pika types is omitted. Voles and pikas are not eaten; therefore, the contact route of infecting humans in these foci is impossible. The second way of transmission of the pathogen to humans – vector-borne – is difficult due to the lack of migration of vole fleas from burrows to the surface and their low efficiency as vectors. Nevertheless, cases of human infection with rhamnose-positive strains of the plague agent in the Caucasus and Mongolia give grounds to assert that at least some rhamnose-positive strains have a sufficiently high virulence and are capable of causing infectious process in humans as well. Therefore, epidemiological surveillance in the foci of plague of the vole and pika types cannot be totally abandoned. It can be conducted according to an abbreviated scheme.
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Konyshev IV, Ivanov SA, Kopylov PH, Anisimov AP, Dentovskaya SV, Byvalov AA. The Role of Yersinia pestis Antigens in Adhesion to J774 Macrophages: Optical Trapping Study. APPL BIOCHEM MICRO+ 2022. [DOI: 10.1134/s0003683822040081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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7
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Hermansen S, Ryoo D, Orwick-Rydmark M, Saragliadis A, Gumbart JC, Linke D. The Role of Extracellular Loops in the Folding of Outer Membrane Protein X (OmpX) of Escherichia coli. Front Mol Biosci 2022; 9:918480. [PMID: 35911955 PMCID: PMC9329534 DOI: 10.3389/fmolb.2022.918480] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 06/16/2022] [Indexed: 11/25/2022] Open
Abstract
The outer membrane of Gram-negative bacteria acts as an additional diffusion barrier for solutes and nutrients. It is perforated by outer membrane proteins (OMPs) that function most often as diffusion pores, but sometimes also as parts of larger cellular transport complexes, structural components of the cell wall, or even as enzymes. These OMPs often have large loops that protrude into the extracellular environment, which have promise for biotechnological applications and as therapeutic targets. Thus, understanding how modifications to these loops affect OMP stability and folding is critical for their efficient application. In this work, the small outer membrane protein OmpX was used as a model system to quantify the effects of loop insertions on OMP folding and stability. The insertions were varied according to both hydrophobicity and size, and their effects were determined by assaying folding into detergent micelles in vitro by SDS-PAGE and in vivo by isolating the outer membrane of cells expressing the constructs. The different insertions were also examined in molecular dynamics simulations to resolve how they affect OmpX dynamics in its native outer membrane. The results indicate that folding of OMPs is affected by both the insert length and by its hydrophobic character. Small insertions sometimes even improved the folding efficiency of OmpX, while large hydrophilic inserts reduced it. All the constructs that were found to fold in vitro could also do so in their native environment. One construct that could not fold in vitro was transported to the OM in vivo, but remained unfolded. Our results will help to improve the design and efficiency of recombinant OMPs used for surface display.
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Affiliation(s)
- Simen Hermansen
- Section for Genetics and Evolutionary Biology, Department of Biosciences, University of Oslo, Oslo, Norway
| | - David Ryoo
- Interdisciplinary Bioengineering Graduate Program, Georgia Institute of Technology, Atlanta, GA, United States
| | - Marcella Orwick-Rydmark
- Section for Genetics and Evolutionary Biology, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Athanasios Saragliadis
- Section for Genetics and Evolutionary Biology, Department of Biosciences, University of Oslo, Oslo, Norway
| | - James C. Gumbart
- School of Physics, Georgia Institute of Technology, Atlanta, GA, United States
| | - Dirk Linke
- Section for Genetics and Evolutionary Biology, Department of Biosciences, University of Oslo, Oslo, Norway
- *Correspondence: Dirk Linke,
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8
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Kolodziejek AM, Hovde CJ, Minnich SA. Contributions of Yersinia pestis outer membrane protein Ail to plague pathogenesis. Curr Opin Infect Dis 2022; 35:188-195. [PMID: 35665712 PMCID: PMC9186061 DOI: 10.1097/qco.0000000000000830] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW Pathogenic Yersinia have been a productive model system for studying bacterial pathogenesis. Hallmark contributions of Yersinia research to medical microbiology are legion and include: (i) the first identification of the role of plasmids in virulence, (ii) the important mechanism of iron acquisition from the host, (iii) the first identification of bacterial surface proteins required for host cell invasion, (iv) the archetypical type III secretion system, and (v) elucidation of the role of genomic reduction in the evolutionary trajectory from a fairly innocuous pathogen to a highly virulent species. RECENT FINDINGS The outer membrane (OM) protein Ail (attachment invasion locus) was identified over 30 years ago as an invasin-like protein. Recent work on Ail continues to provide insights into Gram-negative pathogenesis. This review is a synopsis of the role of Ail in invasion, serum resistance, OM stability, thermosensing, and vaccine development. SUMMARY Ail is shown to be an essential virulence factor with multiple roles in pathogenesis. The recent adaptation of Yersinia pestis to high virulence, which included genomic reduction to eliminate redundant protein functions, is a model to understand the emergence of new bacterial pathogens.
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Affiliation(s)
- Anna M. Kolodziejek
- Department of Animal, Veterinary, and Food Science, University of Idaho, Moscow, Idaho, USA
| | - Carolyn J. Hovde
- Department of Animal, Veterinary, and Food Science, University of Idaho, Moscow, Idaho, USA
| | - Scott A. Minnich
- Department of Animal, Veterinary, and Food Science, University of Idaho, Moscow, Idaho, USA
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9
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Hermansen S, Linke D, Leo JC. Transmembrane β-barrel proteins of bacteria: From structure to function. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2022; 128:113-161. [PMID: 35034717 DOI: 10.1016/bs.apcsb.2021.07.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The outer membrane of Gram-negative bacteria is a specialized organelle conferring protection to the cell against various environmental stresses and resistance to many harmful compounds. The outer membrane has a number of unique features, including an asymmetric lipid bilayer, the presence of lipopolysaccharides and an individual proteome. The vast majority of the integral transmembrane proteins in the outer membrane belongs to the family of β-barrel proteins. These evolutionarily related proteins share a cylindrical, anti-parallel β-sheet core fold spanning the outer membrane. The loops and accessory domains attached to the β-barrel allow for a remarkable versatility in function for these proteins, ranging from diffusion pores and transporters to enzymes and adhesins. We summarize the current knowledge on β-barrel structure and folding and give an overview of their functions, evolution, and potential as drug targets.
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Affiliation(s)
- Simen Hermansen
- Section for Genetics and Evolutionary Biology, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Dirk Linke
- Section for Genetics and Evolutionary Biology, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Jack C Leo
- Antimicrobial resistance, Omics and Microbiota Group, Department of Biosciences, Nottingham Trent University, Nottingham, United Kingdom.
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Deletion of Yersinia pestis ail causes temperature sensitive pleiotropic effects including cell lysis that are suppressed by carbon source, cations, or loss of phospholipase A activity. J Bacteriol 2021; 203:e0036121. [PMID: 34398663 PMCID: PMC8508112 DOI: 10.1128/jb.00361-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Maintenance of phospholipid (PL) and lipopoly- or lipooligo-saccharide (LPS or LOS) asymmetry in the outer membrane (OM) of Gram-negative bacteria is essential but poorly understood. The Yersinia pestis OM Ail protein was required to maintain lipid homeostasis and cell integrity at elevated temperature (37° C). Loss of this protein had pleiotropic effects. A Y. pestis Δail mutant and KIM6+ wild- type were systematically compared for (i) growth requirements at 37° C, (ii) cell structure, (iii) antibiotic and detergent sensitivity, (iv) proteins released into supernates, (v) induction of the heat shock response, and (vi) physiological and genetic suppressors that restored the wild- type phenotype. The Δail mutant grew normally at 28° C but lysed at 37° C when it entered stationary phase as shown by cell count, SDS-PAGE of cell supernatants, and electron microscopy. Immuno-fluorescent microscopy showed that the Δail mutant did not assemble Caf1 capsule. Expression of heat shock promoters rpoE or rpoH fused to a lux operon reporter were not induced when the Δail mutant was shifted from the 28° C to 37° C (p<0.001 and p<0.01 respectively). Mutant lysis was suppressed by addition of 11 mM glucose, 22 or 44 mM glycerol, 2.5 mM Ca2+, or 2.5 mM Mg2+ to the growth medium, or by a mutation in the phospholipase A gene (pldA::miniTn5, ΔpldA, or PldAS164A). A model, accounting for the temperature-sensitive lysis of the Δail mutant and the Ail-dependent stabilization of the OM tetraacylated LOS at 37°C is presented. IMPORTANCE The Gram-negative pathogen, Yersinia pestis, transitions between a flea vector (ambient temperature) and a mammalian host (37° C). In response to 37° C, Y. pestis modifies its outer membrane (OM) by reducing the fatty acid content in lipid A, changing the outer leaflet from being predominantly hexaacylated to being predominantly tetraacylated. It also increases the Ail concentration, so it becomes the most prominent OM protein. Both measures are needed for Y. pestis to evade the host innate immune response. Deletion of ail destabilizes the OM at 37° C causing the cells to lyse. These results show that a protein is essential for maintaining lipid asymmetry and lipid homeostasis in the bacterial OM.
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Roles of OmpX, an Outer Membrane Protein, on Virulence and Flagellar Expression in Uropathogenic Escherichia coli. Infect Immun 2021; 89:IAI.00721-20. [PMID: 33753414 DOI: 10.1128/iai.00721-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 03/12/2021] [Indexed: 01/09/2023] Open
Abstract
Uropathogenic Escherichia coli (UPEC) is a major pathogen that causes urinary tract infection (UTI). This bacterium adheres to and internalizes within urinary tract cells, where it aggregates and subsequently forms biofilm-like multicellular colonies that protect UPEC from antimicrobial agents and the host's immune system. Here, we show that OmpX, an outer membrane protein, plays a role in the pathogenesis of UPEC in renal cells. Deletion of ompX decreased bacterial internalization and aggregation within kidney epithelial cells and also impaired the colonization of mouse urinary tracts, but the ompX mutant still adhered to the epithelial cells at a level similar to that of the parent strain. FlhD, the master regulator of flagellum-related genes, had a low expression level in the ompX mutant compared to the parent strain, and the ompX mutant exhibited defective motility due to lower flagellar production than the parent strain. The fliC mutant, which lacks flagella, exhibited lower levels of bacterial internalization and aggregation than the parent strain. Additional deletion of ompX in the fliC mutant did not further decrease bacterial internalization. These combined results suggest that OmpX contributes to flagellar production in UPEC and then sustains UPEC virulence associated with bacterial internalization and aggregation within urinary tract cells and colonization in the urinary tract.
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12
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Suntsov VV. Genomogenesis of the Plague Bacteria Yersinia pestis as a Process of Mosaic Evolution. RUSS J GENET+ 2021. [DOI: 10.1134/s1022795421020113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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13
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Fujita A, Oogai Y, Kawada-Matsuo M, Nakata M, Noguchi K, Komatsuzawa H. Expression of virulence factors under different environmental conditions in Aggregatibacter actinomycetemcomitans. Microbiol Immunol 2021; 65:101-114. [PMID: 33591576 DOI: 10.1111/1348-0421.12864] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 11/13/2020] [Accepted: 11/19/2020] [Indexed: 11/28/2022]
Abstract
Aggregatibacter actinomycetemcomitans is a facultative anaerobic Gram-negative bacterium associated with periodontal diseases, especially aggressive periodontitis. The virulence factors of this pathogen, including adhesins, exotoxins, and endotoxin, have been extensively studied. However, little is known about their gene expression mode in the host. Herein, we investigated whether culture conditions reflecting in vivo environments, including serum and saliva, alter expression levels of virulence genes in the strain HK1651, a JP2 clone. Under aerobic conditions, addition of calf serum (CS) into a general medium induced high expression of two outer membrane proteins (omp100 and omp64). The high expression of omp100 and omp64 was also induced by an iron-limited medium. RNA-seq analysis showed that the gene expressions of several factors involved in iron acquisition were increased in the CS-containing medium. When HK1651 was grown on agar plates, genes encoding many virulence factors, including the Omps, cytolethal distending toxin, and leukotoxin, were differentially expressed. Then, we investigated their expression in five other A. actinomycetemcomitans strains grown in general and CS-containing media. The expression pattern of virulence factors varied among strains. Compared with the other five strains, HK1561 showed high expression of omp29 regardless of the CS addition, while the gene expression of leukotoxin in HK1651 was higher only in the medium without CS. HK1651 showed reduced biofilm in both CS- and saliva-containing media. Coaggregation with Fusobacterium nucleatum was remarkably enhanced using HK1651 grown in the CS-containing medium. Our results indicate that the expression of virulence factors is altered by adaptation to different conditions during infection.
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Affiliation(s)
- Ayumi Fujita
- Department of Periodontology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Yuichi Oogai
- Department of Oral Microbiology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Miki Kawada-Matsuo
- Department of Bacteriology, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
| | - Masanobu Nakata
- Department of Oral Microbiology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Kazuyuki Noguchi
- Department of Periodontology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Hitoshi Komatsuzawa
- Department of Bacteriology, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
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14
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Hinnebusch BJ, Jarrett CO, Bland DM. Molecular and Genetic Mechanisms That Mediate Transmission of Yersinia pestis by Fleas. Biomolecules 2021; 11:210. [PMID: 33546271 PMCID: PMC7913351 DOI: 10.3390/biom11020210] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 01/26/2021] [Accepted: 01/27/2021] [Indexed: 12/19/2022] Open
Abstract
The ability to cause plague in mammals represents only half of the life history of Yersinia pestis. It is also able to colonize and produce a transmissible infection in the digestive tract of the flea, its insect host. Parallel to studies of the molecular mechanisms by which Y. pestis is able to overcome the immune response of its mammalian hosts, disseminate, and produce septicemia, studies of Y. pestis-flea interactions have led to the identification and characterization of important factors that lead to transmission by flea bite. Y. pestis adapts to the unique conditions in the flea gut by altering its metabolic physiology in ways that promote biofilm development, a common strategy by which bacteria cope with a nutrient-limited environment. Biofilm localization to the flea foregut disrupts normal fluid dynamics of blood feeding, resulting in regurgitative transmission. Many of the important genes, regulatory pathways, and molecules required for this process have been identified and are reviewed here.
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Affiliation(s)
- B. Joseph Hinnebusch
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT 59840, USA; (C.O.J.); (D.M.B.)
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15
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Jelinkova P, Hrdy J, Markova J, Dresler J, Pajer P, Pavlis O, Branich P, Borilova G, Reichelova M, Babak V, Reslova N, Kralik P. Development and Inter-Laboratory Validation of Diagnostics Panel for Detection of Biothreat Bacteria Based on MOL-PCR Assay. Microorganisms 2020; 9:microorganisms9010038. [PMID: 33374468 PMCID: PMC7823616 DOI: 10.3390/microorganisms9010038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 12/16/2020] [Accepted: 12/22/2020] [Indexed: 11/16/2022] Open
Abstract
Early detection of biohazardous bacteria that can be misused as biological weapons is one of the most important measures to prevent the spread and outbreak of biological warfare. For this reason, many instrument platforms need to be introduced into operation in the field of biological warfare detection. Therefore the purpose of this study is to establish a new detection panel for biothreat bacteria (Bacillus anthracis, Yersinia pestis, Francisella tularensis, and Brucella spp.) and confirm it by collaborative validation by using a multiplex oligonucleotide ligation followed by polymerase chain reaction and hybridization to microspheres by MagPix detection platform (MOL-PCR). Appropriate specific sequences in bacterial DNA were selected and tested to assemble the detection panel, and MOLigo probes (short specific oligonucleotides) were designed to show no cross-reactivity when tested between bacteria and to decrease the background signal measurement on the MagPix platform. During testing, sensitivity was assessed for all target bacteria using serially diluted DNA and was determined to be at least 0.5 ng/µL. For use as a diagnostic kit and easier handling, the storage stability of ligation premixes (MOLigo probe mixes) was tested. This highly multiplex method can be used for rapid screening to prevent outbreaks arising from the use of bacterial strains for bioterrorism, because time of analysis take under 4 h.
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Affiliation(s)
- Pavlina Jelinkova
- Department of Microbiology and Antimicrobial Resistance, Veterinary Research Institute, Hudcova 296/70, 621 00 Brno, Czech Republic; (J.H.); (J.M.); (M.R.); (V.B.)
- Correspondence:
| | - Jakub Hrdy
- Department of Microbiology and Antimicrobial Resistance, Veterinary Research Institute, Hudcova 296/70, 621 00 Brno, Czech Republic; (J.H.); (J.M.); (M.R.); (V.B.)
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic
| | - Jirina Markova
- Department of Microbiology and Antimicrobial Resistance, Veterinary Research Institute, Hudcova 296/70, 621 00 Brno, Czech Republic; (J.H.); (J.M.); (M.R.); (V.B.)
| | - Jiri Dresler
- Military Health Institute, Military Medical Agency, Tychonova 1, 160 01 Prague 6, Czech Republic; (J.D.); (P.P.); (O.P.)
| | - Petr Pajer
- Military Health Institute, Military Medical Agency, Tychonova 1, 160 01 Prague 6, Czech Republic; (J.D.); (P.P.); (O.P.)
| | - Oto Pavlis
- Military Health Institute, Military Medical Agency, Tychonova 1, 160 01 Prague 6, Czech Republic; (J.D.); (P.P.); (O.P.)
| | - Pavel Branich
- Military Veterinary Institute, Opavska 29, 748 01 Hlucin, Czech Republic;
| | - Gabriela Borilova
- Department of Meat Hygiene and Technology, Faculty of Veterinary Hygiene and Ecology, University of Veterinary and Pharmaceutical Sciences Brno, Palackeho tr. 1946/1, 612 42 Brno, Czech Republic; (G.B.); (P.K.)
| | - Marketa Reichelova
- Department of Microbiology and Antimicrobial Resistance, Veterinary Research Institute, Hudcova 296/70, 621 00 Brno, Czech Republic; (J.H.); (J.M.); (M.R.); (V.B.)
- Collection of Animal Pathogenic Microorganisms, Department of Bacteriology, Veterinary Research Institute, Hudcova 296/70, 621 00 Brno, Czech Republic
| | - Vladimir Babak
- Department of Microbiology and Antimicrobial Resistance, Veterinary Research Institute, Hudcova 296/70, 621 00 Brno, Czech Republic; (J.H.); (J.M.); (M.R.); (V.B.)
| | - Nikol Reslova
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlarska 2, 611 37 Brno, Czech Republic;
| | - Petr Kralik
- Department of Meat Hygiene and Technology, Faculty of Veterinary Hygiene and Ecology, University of Veterinary and Pharmaceutical Sciences Brno, Palackeho tr. 1946/1, 612 42 Brno, Czech Republic; (G.B.); (P.K.)
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16
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Kent JE, Fujimoto LM, Shin K, Singh C, Yao Y, Park SH, Opella SJ, Plano GV, Marassi FM. Correlating the Structure and Activity of Y. pestis Ail in a Bacterial Cell Envelope. Biophys J 2020; 120:453-462. [PMID: 33359463 DOI: 10.1016/j.bpj.2020.12.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 12/08/2020] [Accepted: 12/16/2020] [Indexed: 11/16/2022] Open
Abstract
Understanding microbe-host interactions at the molecular level is a major goal of fundamental biology and therapeutic drug development. Structural biology strives to capture biomolecular structures in action, but the samples are often highly simplified versions of the complex native environment. Here, we present an Escherichia coli model system that allows us to probe the structure and function of Ail, the major surface protein of the deadly pathogen Yersinia pestis. We show that cell surface expression of Ail produces Y. pestis virulence phenotypes in E. coli, including resistance to human serum, cosedimentation of human vitronectin, and pellicle formation. Moreover, isolated bacterial cell envelopes, encompassing inner and outer membranes, yield high-resolution solid-state NMR spectra that reflect the structure of Ail and reveal Ail sites that are sensitive to the bacterial membrane environment and involved in the interactions with human serum components. The data capture the structure and function of Ail in a bacterial outer membrane and set the stage for probing its interactions with the complex milieu of immune response proteins present in human serum.
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Affiliation(s)
- James E Kent
- Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California
| | - Lynn M Fujimoto
- Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California
| | - Kyungsoo Shin
- Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California
| | - Chandan Singh
- Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California
| | - Yong Yao
- Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California
| | - Sang Ho Park
- Department Chemistry and Biochemistry, University of California, San Diego, La Jolla, California
| | - Stanley J Opella
- Department Chemistry and Biochemistry, University of California, San Diego, La Jolla, California
| | - Gregory V Plano
- Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, Florida
| | - Francesca M Marassi
- Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California.
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17
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Early evolutionary loss of the lipid A modifying enzyme PagP resulting in innate immune evasion in Yersinia pestis. Proc Natl Acad Sci U S A 2020; 117:22984-22991. [PMID: 32868431 DOI: 10.1073/pnas.1917504117] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Immune evasion through membrane remodeling is a hallmark of Yersinia pestis pathogenesis. Yersinia remodels its membrane during its life cycle as it alternates between mammalian hosts (37 °C) and ambient (21 °C to 26 °C) temperatures of the arthropod transmission vector or external environment. This shift in growth temperature induces changes in number and length of acyl groups on the lipid A portion of lipopolysaccharide (LPS) for the enteric pathogens Yersinia pseudotuberculosis (Ypt) and Yersinia enterocolitica (Ye), as well as the causative agent of plague, Yersinia pestis (Yp). Addition of a C16 fatty acid (palmitate) to lipid A by the outer membrane acyltransferase enzyme PagP occurs in immunostimulatory Ypt and Ye strains, but not in immune-evasive Yp Analysis of Yp pagP gene sequences identified a single-nucleotide polymorphism that results in a premature stop in translation, yielding a truncated, nonfunctional enzyme. Upon repair of this polymorphism to the sequence present in Ypt and Ye, lipid A isolated from a Yp pagP+ strain synthesized two structures with the C16 fatty acids located in acyloxyacyl linkage at the 2' and 3' positions of the diglucosamine backbone. Structural modifications were confirmed by mass spectrometry and gas chromatography. With the genotypic restoration of PagP enzymatic activity in Yp, a significant increase in lipid A endotoxicity mediated through the MyD88 and TRIF/TRAM arms of the TLR4-signaling pathway was observed. Discovery and repair of an evolutionarily lost lipid A modifying enzyme provides evidence of lipid A as a crucial determinant in Yp infectivity, pathogenesis, and host innate immune evasion.
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18
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Tn-Seq Analysis Identifies Genes Important for Yersinia pestis Adherence during Primary Pneumonic Plague. mSphere 2020; 5:5/4/e00715-20. [PMID: 32759339 PMCID: PMC7407073 DOI: 10.1128/msphere.00715-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Colonization of the lung by Yersinia pestis is a critical first step in establishing infection during primary pneumonic plague, a disease characterized by high lethality. However, the mechanisms by which Y. pestis adheres in the lung after inhalation remain elusive. Here, we used Tn-seq to identify Y. pestis genes important for adherence early during primary pneumonic plague. Our mutant enrichment strategy resulted in the identification of genes important for regulation and assembly of genes and proteins rather than adhesin genes themselves. These results reveal that there may be multiple Y. pestis adhesins or redundancy among adhesins. Identifying the adhesins regulated by the genes identified in our enrichment screen may reveal novel therapeutic targets for preventing Y. pestis adherence and the subsequent development of pneumonic plague. Following inhalation, Yersinia pestis rapidly colonizes the lung to establish infection during primary pneumonic plague. Although several adhesins have been identified in Yersinia spp., the factors mediating early Y. pestis adherence in the lung remain unknown. To identify genes important for Y. pestis adherence during primary pneumonic plague, we used transposon insertion sequencing (Tn-seq). Wild-type and capsule mutant (Δcaf1) Y. pestis transposon mutant libraries were serially passaged in vivo to enrich for nonadherent mutants in the lung using a mouse model of primary pneumonic plague. Sequencing of the passaged libraries revealed six mutants that were significantly enriched in both the wild-type and Δcaf1Y. pestis backgrounds. The enriched mutants had insertions in genes that encode transcriptional regulators, chaperones, an endoribonuclease, and YPO3903, a hypothetical protein. Using single-strain infections and a transcriptional analysis, we identified a significant role for YPO3903 in Y. pestis adherence in the lung and showed that YPO3903 regulated transcript levels of psaA, which encodes a fimbria previously implicated in Y. pestis adherence in vitro. Deletion of psaA had a minor effect on Y. pestis adherence in the lung, suggesting that YPO3903 regulates other adhesins in addition to psaA. By enriching for mutations in genes that regulate the expression or assembly of multiple genes or proteins, we obtained screen results indicating that there may be not just one dominant adhesin but rather several factors that contribute to early Y. pestis adherence during primary pneumonic plague. IMPORTANCE Colonization of the lung by Yersinia pestis is a critical first step in establishing infection during primary pneumonic plague, a disease characterized by high lethality. However, the mechanisms by which Y. pestis adheres in the lung after inhalation remain elusive. Here, we used Tn-seq to identify Y. pestis genes important for adherence early during primary pneumonic plague. Our mutant enrichment strategy resulted in the identification of genes important for regulation and assembly of genes and proteins rather than adhesin genes themselves. These results reveal that there may be multiple Y. pestis adhesins or redundancy among adhesins. Identifying the adhesins regulated by the genes identified in our enrichment screen may reveal novel therapeutic targets for preventing Y. pestis adherence and the subsequent development of pneumonic plague.
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19
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Singh C, Lee H, Tian Y, Schesser Bartra S, Hower S, Fujimoto LM, Yao Y, Ivanov SA, Shaikhutdinova RZ, Anisimov AP, Plano GV, Im W, Marassi FM. Mutually constructive roles of Ail and LPS in Yersinia pestis serum survival. Mol Microbiol 2020; 114:510-520. [PMID: 32462782 DOI: 10.1111/mmi.14530] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 05/17/2020] [Accepted: 05/18/2020] [Indexed: 01/12/2023]
Abstract
The outer membrane is a key virulence determinant of gram-negative bacteria. In Yersinia pestis, the deadly agent that causes plague, the protein Ail and lipopolysaccharide (LPS)6 enhance lethality by promoting resistance to human innate immunity and antibiotics, enabling bacteria to proliferate in the human host. Their functions are highly coordinated. Here we describe how they cooperate to promote pathogenesis. Using a multidisciplinary approach, we identify mutually constructive interactions between Ail and LPS that produce an extended conformation of Ail at the membrane surface, cause thickening and rigidification of the LPS membrane, and collectively promote Y. pestis survival in human serum, antibiotic resistance, and cell envelope integrity. The results highlight the importance of the Ail-LPS assembly as an organized whole, rather than its individual components, and provide a handle for targeting Y. pestis pathogenesis.
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Affiliation(s)
- Chandan Singh
- Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Hwayoung Lee
- Department of Biological Sciences, Chemistry, and Bioengineering, Lehigh University, Bethlehem, PA, USA
| | - Ye Tian
- Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Sara Schesser Bartra
- Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Suzanne Hower
- Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Lynn M Fujimoto
- Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Yong Yao
- Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Sergey A Ivanov
- State Research Center for Applied Microbiology and Biotechnology, Obolensk, Moscow Region, Russian Federation
| | - Rima Z Shaikhutdinova
- State Research Center for Applied Microbiology and Biotechnology, Obolensk, Moscow Region, Russian Federation
| | - Andrey P Anisimov
- State Research Center for Applied Microbiology and Biotechnology, Obolensk, Moscow Region, Russian Federation
| | - Gregory V Plano
- Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Wonpil Im
- Department of Biological Sciences, Chemistry, and Bioengineering, Lehigh University, Bethlehem, PA, USA
| | - Francesca M Marassi
- Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
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20
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Gupta A, Mahalakshmi R. Single-residue physicochemical characteristics kinetically partition membrane protein self-assembly and aggregation. J Biol Chem 2020. [DOI: 10.1016/s0021-9258(17)49878-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
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21
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Gupta A, Mahalakshmi R. Single-residue physicochemical characteristics kinetically partition membrane protein self-assembly and aggregation. J Biol Chem 2019; 295:1181-1194. [PMID: 31844019 PMCID: PMC6996891 DOI: 10.1074/jbc.ra119.011342] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 12/11/2019] [Indexed: 11/06/2022] Open
Abstract
Ninety-five percent of all transmembrane proteins exist in kinetically trapped aggregation-prone states that have been directly linked to neurodegenerative diseases. Interestingly, the primary sequence almost invariably avoids off-pathway aggregate formation, by folding reliably into its native, thermodynamically stabilized structure. However, with the rising incidence of protein aggregation diseases, it is now important to understand the underlying mechanism(s) of membrane protein aggregation. Micromolecular physicochemical and biochemical alterations in the primary sequence that trigger the formation of macromolecular cross-β aggregates can be measured only through combinatorial spectroscopic experiments. Here, we developed spectroscopic thermal perturbation with 117 experimental variables to assess how subtle protein sequence variations drive the molecular transition of the folded protein to oligomeric aggregates. Using the Yersinia pestis outer transmembrane β-barrel Ail as a model, we delineated how a single-residue substitution that alters the membrane-anchoring ability of Ail significantly contributes to the kinetic component of Ail stability. We additionally observed a stabilizing role for interface aliphatics, and that interface aromatics physicochemically contribute to Ail self-assembly and aggregation. Moreover, our method identified the formation of structured oligomeric intermediates during Ail aggregation. We show that the self-aggregation tendency of Ail is offset by the evolution of a thermodynamically compromised primary sequence that balances folding, stability, and oligomerization. Our approach provides critical information on how subtle changes in protein primary sequence trigger cross-β fibril formation, with insights that have direct implications for deducing the molecular progression of neurodegeneration and amyloidogenesis in humans.
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Affiliation(s)
- Ankit Gupta
- Molecular Biophysics Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research, Bhopal 462066, India
| | - Radhakrishnan Mahalakshmi
- Molecular Biophysics Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research, Bhopal 462066, India
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22
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Vaca DJ, Thibau A, Schütz M, Kraiczy P, Happonen L, Malmström J, Kempf VAJ. Interaction with the host: the role of fibronectin and extracellular matrix proteins in the adhesion of Gram-negative bacteria. Med Microbiol Immunol 2019; 209:277-299. [PMID: 31784893 PMCID: PMC7248048 DOI: 10.1007/s00430-019-00644-3] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 11/14/2019] [Indexed: 01/03/2023]
Abstract
The capacity of pathogenic microorganisms to adhere to host cells and avoid clearance by the host immune system is the initial and most decisive step leading to infections. Bacteria have developed different strategies to attach to diverse host surface structures. One important strategy is the adhesion to extracellular matrix (ECM) proteins (e.g., collagen, fibronectin, laminin) that are highly abundant in connective tissue and basement membranes. Gram-negative bacteria express variable outer membrane proteins (adhesins) to attach to the host and to initiate the process of infection. Understanding the underlying molecular mechanisms of bacterial adhesion is a prerequisite for targeting this interaction by “anti-ligands” to prevent colonization or infection of the host. Future development of such “anti-ligands” (specifically interfering with bacteria-host matrix interactions) might result in the development of a new class of anti-infective drugs for the therapy of infections caused by multidrug-resistant Gram-negative bacteria. This review summarizes our current knowledge about the manifold interactions of adhesins expressed by Gram-negative bacteria with ECM proteins and the use of this information for the generation of novel therapeutic antivirulence strategies.
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Affiliation(s)
- Diana J Vaca
- Institute for Medical Microbiology and Infection Control, University Hospital, Goethe University Frankfurt am Main, Paul-Ehrlich-Str. 40, 60596, Frankfurt, Germany
| | - Arno Thibau
- Institute for Medical Microbiology and Infection Control, University Hospital, Goethe University Frankfurt am Main, Paul-Ehrlich-Str. 40, 60596, Frankfurt, Germany
| | - Monika Schütz
- Institute for Medical Microbiology and Infection Control, University Hospital, Eberhard Karls-University, Tübingen, Germany
| | - Peter Kraiczy
- Institute for Medical Microbiology and Infection Control, University Hospital, Goethe University Frankfurt am Main, Paul-Ehrlich-Str. 40, 60596, Frankfurt, Germany
| | - Lotta Happonen
- Division of Infection Medicine, Department of Clinical Sciences, Faculty of Medicine, Lund University, Lund, Sweden
| | - Johan Malmström
- Division of Infection Medicine, Department of Clinical Sciences, Faculty of Medicine, Lund University, Lund, Sweden
| | - Volkhard A J Kempf
- Institute for Medical Microbiology and Infection Control, University Hospital, Goethe University Frankfurt am Main, Paul-Ehrlich-Str. 40, 60596, Frankfurt, Germany.
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23
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Abstract
The human and animal pathogens Yersinia pestis, which causes bubonic and pneumonic plague, and Yersinia pseudotuberculosis and Yersinia enterocolitica, which cause gastroenteritis, share a type 3 secretion system which injects effector proteins, Yops, into host cells. This system is critical for virulence of all three pathogens in tissue infection. Neutrophils are rapidly recruited to infected sites and all three pathogens frequently interact with and inject Yops into these cells during tissue infection. Host receptors, serum factors, and bacterial adhesins appear to collaborate to promote neutrophil- Yersinia interactions in tissues. The ability of neutrophils to control infection is mixed depending on the stage of infection and points to the efficiency of Yops and other bacterial factors to mitigate bactericidal effects of neutrophils. Yersinia in close proximity to neutrophils has higher levels of expression from yop promoters, and neutrophils in close proximity to Yersinia express higher levels of pro-survival genes than migrating neutrophils. In infected tissues, YopM increases neutrophil survival and YopH targets a SKAP2/SLP-76 signal transduction pathway. Yet the full impact of these and other Yops and other Yersinia factors on neutrophils in infected tissues has yet to be understood.
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Affiliation(s)
- Joan Mecsas
- Department of Molecular Biology and Microbiology, 136 Harrison Ave, Tufts University School of Medicine, Boston, MA, 02111, USA
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24
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Rabaan AA, Al-Ahmed SH, Alsuliman SA, Aldrazi FA, Alfouzan WA, Haque S. The rise of pneumonic plague in Madagascar: current plague outbreak breaks usual seasonal mould. J Med Microbiol 2019; 68:292-302. [PMID: 30632956 DOI: 10.1099/jmm.0.000915] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Madagascar has just emerged from the grip of an acute urban pneumonic plague outbreak, which began in August 2017, before the usual plague season of October-April and outside the traditional plague foci in the northern and central highlands. The World Health Organization reported a total of 2417 confirmed, probable and suspected cases, including 209 deaths between 1 August and 26 November 2017. The severity and scope of this outbreak, which has affected those in higher socioeconomic groups as well as those living in poverty, along with factors including the potential for use of multi-drug-resistant strains of plague in bioterrorism, highlights the ongoing threat posed by this ancient disease. Factors likely to have contributed to transmission include human behaviour, including burial practices and movement of people, poor urban planning leading to overcrowding and ready transmission by airborne droplets, climatic factors and genomic subtypes. The outbreak demonstrates the importance of identifying targeted pneumonic plague therapies and of developing vaccines that can be administered in planned programmes in developing countries such as Madagascar where plague is endemic. The dominance of pneumonic plague in this outbreak suggests that we need to focus more urgently on the danger of person-to-person transmission, as well as the problem of transmission of plague from zoonotic sources.
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Affiliation(s)
- Ali A Rabaan
- 1Molecular Diagnostic Laboratory, Johns Hopkins Aramco Healthcare, Dhahran, Saudi Arabia
| | - Shamsah H Al-Ahmed
- 2Specialty Paediatric Medicine, Qatif Central Hospital, Qatif, Saudi Arabia
| | - Shahab A Alsuliman
- 3Internal Medicine and Infectious Disease Department, Dammam Medical Complex, Dammam, Saudi Arabia
| | - Fatimah A Aldrazi
- 4Infection Control Department, Dammam Medical Complex, Dammam, Saudi Arabia
| | - Wadha A Alfouzan
- 5Department of Microbiology, Faculty of Medicine, Kuwait University, Safat 13110, Kuwait
| | - Shafiul Haque
- 6Research and Scientific Studies Unit, College of Nursing & Allied Health Sciences, Jazan University, Jazan, Saudi Arabia
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25
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Hinnebusch BJ, Jarrett CO, Bland DM. "Fleaing" the Plague: Adaptations of Yersinia pestis to Its Insect Vector That Lead to Transmission. Annu Rev Microbiol 2018; 71:215-232. [PMID: 28886687 DOI: 10.1146/annurev-micro-090816-093521] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Interest in arthropod-borne pathogens focuses primarily on how they cause disease in humans. How they produce a transmissible infection in their arthropod host is just as critical to their life cycle, however. Yersinia pestis adopts a unique life stage in the digestive tract of its flea vector, characterized by rapid formation of a bacterial biofilm that is enveloped in a complex extracellular polymeric substance. Localization and adherence of the biofilm to the flea foregut is essential for transmission. Here, we review the molecular and genetic mechanisms of these processes and present a comparative evaluation and updated model of two related transmission mechanisms.
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Affiliation(s)
- B Joseph Hinnebusch
- Laboratory of Zoonotic Pathogens, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana 59840;
| | - Clayton O Jarrett
- Laboratory of Zoonotic Pathogens, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana 59840;
| | - David M Bland
- Laboratory of Zoonotic Pathogens, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana 59840;
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26
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Puławska J, Kałużna M, Warabieda W, Mikiciński A. Comparative transcriptome analysis of a lowly virulent strain of Erwinia amylovora in shoots of two apple cultivars - susceptible and resistant to fire blight. BMC Genomics 2017; 18:868. [PMID: 29132313 PMCID: PMC5683332 DOI: 10.1186/s12864-017-4251-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 10/31/2017] [Indexed: 12/23/2022] Open
Abstract
Background Erwinia amylovora is generally considered to be a homogeneous species in terms of phenotypic and genetic features. However, strains show variation in their virulence, particularly on hosts with different susceptibility to fire blight. We applied the RNA-seq technique to elucidate transcriptome-level changes of the lowly virulent E. amylovora 650 strain during infection of shoots of susceptible (Idared) and resistant (Free Redstar) apple cultivars. Results The highest number of differentially expressed E. amylovora genes between the two apple genotypes was observed at 24 h after inoculation. Six days after inoculation, only a few bacterial genes were differentially expressed in the susceptible and resistant apple cultivars. The analysis of differentially expressed gene functions showed that generally, higher expression of genes related to stress response and defence against toxic compounds was observed in Free Redstar. Also in this cultivar, higher expression of flagellar genes (FlaI), which are recognized as PAMP (pathogen-associated molecular pattern) by the innate immune systems of plants, was noted. Additionally, several genes that have not yet been proven to play a role in the pathogenic abilities of E. amylovora were found to be differentially expressed in the two apple cultivars. Conclusions This RNA-seq analysis generated a novel dataset describing the transcriptional response of the lowly virulent strain of E. amylovora in susceptible and resistant apple cultivar. Most genes were regulated in the same way in both apple cultivars, but there were also some cultivar-specific responses suggesting that the environment in Free Redstar is more stressful for bacteria what can be the reason of their inability to infect of this cultivar. Among genes with the highest fold change in expression between experimental combinations or with the highest transcript abundance, there are many genes without ascribed functions, which have never been tested for their role in pathogenicity. Overall, this study provides the first transcriptional profile by RNA-seq of E. amylovora during infection of a host plant and insights into the transcriptional response of this pathogen in the environments of susceptible and resistant apple plants. Electronic supplementary material The online version of this article (10.1186/s12864-017-4251-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Joanna Puławska
- Research Institute of Horticulture, ul. Konstytucji 3 Maja 1/3, 96-100, Skierniewice, Poland.
| | - Monika Kałużna
- Research Institute of Horticulture, ul. Konstytucji 3 Maja 1/3, 96-100, Skierniewice, Poland
| | - Wojciech Warabieda
- Research Institute of Horticulture, ul. Konstytucji 3 Maja 1/3, 96-100, Skierniewice, Poland
| | - Artur Mikiciński
- Research Institute of Horticulture, ul. Konstytucji 3 Maja 1/3, 96-100, Skierniewice, Poland
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27
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Ignatov D, Johansson J. RNA-mediated signal perception in pathogenic bacteria. WILEY INTERDISCIPLINARY REVIEWS-RNA 2017; 8. [PMID: 28792118 DOI: 10.1002/wrna.1429] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 05/11/2017] [Accepted: 05/11/2017] [Indexed: 11/09/2022]
Abstract
Bacterial pathogens encounter several different environments during an infection, many of them possibly being detrimental. In order to sense its surroundings and adjust the gene expression accordingly, different regulatory schemes are undertaken. With these, the bacterium appropriately can differentiate between various environmental cues to express the correct virulence factor at the appropriate time and place. An attractive regulator device is RNA, which has an outstanding ability to alter its structure in response to external stimuli, such as metabolite concentration or alterations in temperature, to control its downstream gene expression. This review will describe the function of riboswitches and thermometers, with a particular emphasis on regulatory RNAs being important for bacterial pathogenicity. WIREs RNA 2017, 8:e1429. doi: 10.1002/wrna.1429 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Dmitriy Ignatov
- Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden.,Department of Molecular Biology, Umeå University, Umeå, Sweden.,Laboratory for Molecular Infection Medicine Sweden, Umeå University, Umeå, Sweden
| | - Jörgen Johansson
- Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden.,Department of Molecular Biology, Umeå University, Umeå, Sweden.,Laboratory for Molecular Infection Medicine Sweden, Umeå University, Umeå, Sweden
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28
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Dutta SK, Yao Y, Marassi FM. Structural Insights into the Yersinia pestis Outer Membrane Protein Ail in Lipid Bilayers. J Phys Chem B 2017; 121:7561-7570. [PMID: 28726410 DOI: 10.1021/acs.jpcb.7b03941] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Yersinia pestis the causative agent of plague, is highly pathogenic and poses very high risk to public health. The outer membrane protein Ail (Adhesion invasion locus) is one of the most highly expressed proteins on the cell surface of Y. pestis, and a major target for the development of medical countermeasures. Ail is essential for microbial virulence and is critical for promoting the survival of Y. pestis in serum. Structures of Ail have been determined by X-ray diffraction and solution NMR spectroscopy, but the protein's activity is influenced by the detergents in these samples, underscoring the importance of the surrounding environment for structure-activity studies. Here we describe the backbone structure of Ail, determined in lipid bilayer nanodiscs, using solution NMR spectroscopy. We also present solid-state NMR data obtained for Ail in membranes containing lipopolysaccharide (LPS), a major component of the bacterial outer membranes. The protein in lipid bilayers, adopts the same eight-stranded β-barrel fold observed in the crystalline and micellar states. The membrane composition, however, appears to have a marked effect on protein dynamics, with LPS enhancing conformational order and slowing down the 15N transverse relaxation rate. The results provide information about the way in which an outer membrane protein inserts and functions in the bacterial membrane.
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Affiliation(s)
- Samit Kumar Dutta
- Sanford Burnham Prebys Medical Discovery Institute , 10901 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Yong Yao
- Sanford Burnham Prebys Medical Discovery Institute , 10901 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Francesca M Marassi
- Sanford Burnham Prebys Medical Discovery Institute , 10901 North Torrey Pines Road, La Jolla, California 92037, United States
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Hovingh ES, van den Broek B, Jongerius I. Hijacking Complement Regulatory Proteins for Bacterial Immune Evasion. Front Microbiol 2016; 7:2004. [PMID: 28066340 PMCID: PMC5167704 DOI: 10.3389/fmicb.2016.02004] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 11/30/2016] [Indexed: 12/11/2022] Open
Abstract
The human complement system plays an important role in the defense against invading pathogens, inflammation and homeostasis. Invading microbes, such as bacteria, directly activate the complement system resulting in the formation of chemoattractants and in effective labeling of the bacteria for phagocytosis. In addition, formation of the membrane attack complex is responsible for direct killing of Gram-negative bacteria. In turn, bacteria have evolved several ways to evade complement activation on their surface in order to be able to colonize and invade the human host. One important mechanism of bacterial escape is attraction of complement regulatory proteins to the microbial surface. These molecules are present in the human body for tight regulation of the complement system to prevent damage to host self-surfaces. Therefore, recruitment of complement regulatory proteins to the bacterial surface results in decreased complement activation on the microbial surface which favors bacterial survival. This review will discuss recent advances in understanding the binding of complement regulatory proteins to the bacterial surface at the molecular level. This includes, new insights that have become available concerning specific conserved motives on complement regulatory proteins that are favorable for microbial binding. Finally, complement evasion molecules are of high importance for vaccine development due to their dominant role in bacterial survival, high immunogenicity and homology as well as their presence on the bacterial surface. Here, the use of complement evasion molecules for vaccine development will be discussed.
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Affiliation(s)
- Elise S. Hovingh
- Department of Medical Microbiology, University Medical Center UtrechtUtrecht, Netherlands
- Centre for Infectious Disease Control, National Institute for Public Health and the EnvironmentBilthoven, Netherlands
| | - Bryan van den Broek
- Department of Medical Microbiology, University Medical Center UtrechtUtrecht, Netherlands
| | - Ilse Jongerius
- Department of Medical Microbiology, University Medical Center UtrechtUtrecht, Netherlands
- Centre for Infectious Disease Control, National Institute for Public Health and the EnvironmentBilthoven, Netherlands
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Temperature-responsive in vitro RNA structurome of Yersinia pseudotuberculosis. Proc Natl Acad Sci U S A 2016; 113:7237-42. [PMID: 27298343 DOI: 10.1073/pnas.1523004113] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
RNA structures are fundamentally important for RNA function. Dynamic, condition-dependent structural changes are able to modulate gene expression as shown for riboswitches and RNA thermometers. By parallel analysis of RNA structures, we mapped the RNA structurome of Yersinia pseudotuberculosis at three different temperatures. This human pathogen is exquisitely responsive to host body temperature (37 °C), which induces a major metabolic transition. Our analysis profiles the structure of more than 1,750 RNAs at 25 °C, 37 °C, and 42 °C. Average mRNAs tend to be unstructured around the ribosome binding site. We searched for 5'-UTRs that are folded at low temperature and identified novel thermoresponsive RNA structures from diverse gene categories. The regulatory potential of 16 candidates was validated. In summary, we present a dynamic bacterial RNA structurome and find that the expression of virulence-relevant functions in Y. pseudotuberculosis and reprogramming of its metabolism in response to temperature is associated with a restructuring of numerous mRNAs.
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Chauhan N, Wrobel A, Skurnik M, Leo JC. Yersinia adhesins: An arsenal for infection. Proteomics Clin Appl 2016; 10:949-963. [PMID: 27068449 DOI: 10.1002/prca.201600012] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 03/14/2016] [Accepted: 04/06/2016] [Indexed: 11/09/2022]
Abstract
The Yersiniae are a group of Gram-negative coccobacilli inhabiting a wide range of habitats. The genus harbors three recognized human pathogens: Y. enterocolitica and Y. pseudotuberculosis, which both cause gastrointestinal disease, and Y. pestis, the causative agent of plague. These three organisms have served as models for a number of aspects of infection biology, including adhesion, immune evasion, evolution of pathogenic traits, and retracing the course of ancient pandemics. The virulence of the pathogenic Yersiniae is heavily dependent on a number of adhesin molecules. Some of these, such as the Yersinia adhesin A and invasin of the enteropathogenic species, and the pH 6 antigen of Y. pestis, have been extensively studied. However, genomic sequencing has uncovered a host of other adhesins present in these organisms, the functions of which are only starting to be investigated. Here, we review the current state of knowledge on the adhesin molecules present in the Yersiniae, and their functions and putative roles in the infection process.
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Affiliation(s)
- Nandini Chauhan
- Evolution and Genetics, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Agnieszka Wrobel
- Evolution and Genetics, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Mikael Skurnik
- Department of Bacteriology and Immunology, Medicum, Research Programs Unit, Immunobiology, University of Helsinki, Helsinki, Finland.,Central Hospital Laboratory Diagnostics, Helsinki University, Helsinki, Finland
| | - Jack C Leo
- Evolution and Genetics, Department of Biosciences, University of Oslo, Oslo, Norway.
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32
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Meng X, Liu X, Zhang L, Hou B, Li B, Tan C, Li Z, Zhou R, Li S. Virulence characteristics of extraintestinal pathogenic Escherichia coli deletion of gene encoding the outer membrane protein X. J Vet Med Sci 2016; 78:1261-7. [PMID: 27149893 PMCID: PMC5053926 DOI: 10.1292/jvms.16-0071] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Outer membrane protein X (OmpX) and its homologues have been proposed to contribute to
the virulence in various bacterial species. But, their role in virulence of
extraintestinal pathogenic Escherichia coli (ExPEC) is yet to be
determined. This study evaluates the role of OmpX in ExPEC virulence in
vitro and in vivo using a clinical strain PPECC42 of porcine
origin. The ompX deletion mutant exhibited increased swimming motility
and decreased adhesion to, and invasion of pulmonary epithelial A549 cell, compared to the
wild-type strain. A mild increase in LD50 and distinct decrease in bacterial
load in such organs as heart, liver, spleen, lung and kidney were observed in mice
infected with the ompX mutant. Complementation of the complete
ompX gene in trans restored the virulence of mutant
strain to the level of wild-type strain. Our results reveal that OmpX contributes to ExPEC
virulence, but may be not an indispensable virulence determinant.
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Affiliation(s)
- Xianrong Meng
- State Key Lab of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
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Chen S, Thompson KM, Francis MS. Environmental Regulation of Yersinia Pathophysiology. Front Cell Infect Microbiol 2016; 6:25. [PMID: 26973818 PMCID: PMC4773443 DOI: 10.3389/fcimb.2016.00025] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 02/15/2016] [Indexed: 12/26/2022] Open
Abstract
Hallmarks of Yersinia pathogenesis include the ability to form biofilms on surfaces, the ability to establish close contact with eukaryotic target cells and the ability to hijack eukaryotic cell signaling and take over control of strategic cellular processes. Many of these virulence traits are already well-described. However, of equal importance is knowledge of both confined and global regulatory networks that collaborate together to dictate spatial and temporal control of virulence gene expression. This review has the purpose to incorporate historical observations with new discoveries to provide molecular insight into how some of these regulatory mechanisms respond rapidly to environmental flux to govern tight control of virulence gene expression by pathogenic Yersinia.
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Affiliation(s)
- Shiyun Chen
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences Wuhan, China
| | - Karl M Thompson
- Department of Microbiology, College of Medicine, Howard University Washington, DC, USA
| | - Matthew S Francis
- Umeå Centre for Microbial Research, Umeå UniversityUmeå, Sweden; Department of Molecular Biology, Umeå UniversityUmeå, Sweden
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34
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Leiser OP, Merkley ED, Clowers BH, Deatherage Kaiser BL, Lin A, Hutchison JR, Melville AM, Wagner DM, Keim PS, Foster JT, Kreuzer HW. Investigation of Yersinia pestis Laboratory Adaptation through a Combined Genomics and Proteomics Approach. PLoS One 2015; 10:e0142997. [PMID: 26599979 PMCID: PMC4658026 DOI: 10.1371/journal.pone.0142997] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 10/29/2015] [Indexed: 11/19/2022] Open
Abstract
The bacterial pathogen Yersinia pestis, the cause of plague in humans and animals, normally has a sylvatic lifestyle, cycling between fleas and mammals. In contrast, laboratory-grown Y. pestis experiences a more constant environment and conditions that it would not normally encounter. The transition from the natural environment to the laboratory results in a vastly different set of selective pressures, and represents what could be considered domestication. Understanding the kinds of adaptations Y. pestis undergoes as it becomes domesticated will contribute to understanding the basic biology of this important pathogen. In this study, we performed a parallel serial passage experiment (PSPE) to explore the mechanisms by which Y. pestis adapts to laboratory conditions, hypothesizing that cells would undergo significant changes in virulence and nutrient acquisition systems. Two wild strains were serially passaged in 12 independent populations each for ~750 generations, after which each population was analyzed using whole-genome sequencing, LC-MS/MS proteomic analysis, and GC/MS metabolomics. We observed considerable parallel evolution in the endpoint populations, detecting multiple independent mutations in ail, pepA, and zwf, suggesting that specific selective pressures are shaping evolutionary responses. Complementary LC-MS/MS proteomic data provide physiological context to the observed mutations, and reveal regulatory changes not necessarily associated with specific mutations, including changes in amino acid metabolism and cell envelope biogenesis. Proteomic data support hypotheses generated by genomic data in addition to suggesting future mechanistic studies, indicating that future whole-genome sequencing studies be designed to leverage proteomics as a critical complement.
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Affiliation(s)
- Owen P. Leiser
- Center for Microbial Genetics and Genomics, Northern Arizona University, Flagstaff, AZ, 86001, United States of America
| | - Eric D. Merkley
- Chemical and Biological Signature Sciences, Pacific Northwest National Laboratory, Richland, WA, 99352, United States of America
| | - Brian H. Clowers
- Department of Chemistry, Washington State University, Pullman, WA, 99354, United States of America
| | - Brooke L. Deatherage Kaiser
- Chemical and Biological Signature Sciences, Pacific Northwest National Laboratory, Richland, WA, 99352, United States of America
| | - Andy Lin
- Chemical and Biological Signature Sciences, Pacific Northwest National Laboratory, Richland, WA, 99352, United States of America
| | - Janine R. Hutchison
- Chemical and Biological Signature Sciences, Pacific Northwest National Laboratory, Richland, WA, 99352, United States of America
| | - Angela M. Melville
- Chemical and Biological Signature Sciences, Pacific Northwest National Laboratory, Richland, WA, 99352, United States of America
| | - David M. Wagner
- Center for Microbial Genetics and Genomics, Northern Arizona University, Flagstaff, AZ, 86001, United States of America
| | - Paul S. Keim
- Center for Microbial Genetics and Genomics, Northern Arizona University, Flagstaff, AZ, 86001, United States of America
| | - Jeffrey T. Foster
- Center for Microbial Genetics and Genomics, Northern Arizona University, Flagstaff, AZ, 86001, United States of America
| | - Helen W. Kreuzer
- Chemical and Biological Signature Sciences, Pacific Northwest National Laboratory, Richland, WA, 99352, United States of America
- * E-mail:
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35
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Origins of Yersinia pestis sensitivity to the arylomycin antibiotics and the inhibition of type I signal peptidase. Antimicrob Agents Chemother 2015; 59:3887-98. [PMID: 25896690 DOI: 10.1128/aac.00181-15] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 04/10/2015] [Indexed: 02/04/2023] Open
Abstract
Yersinia pestis is the etiologic agent of the plague. Reports of Y. pestis strains that are resistant to each of the currently approved first-line and prophylactic treatments point to the urgent need to develop novel antibiotics with activity against the pathogen. We previously reported that Y. pestis strain KIM6+, unlike most Enterobacteriaceae, is susceptible to the arylomycins, a novel class of natural-product lipopeptide antibiotics that inhibit signal peptidase I (SPase). In this study, we show that the arylomycin activity is conserved against a broad range of Y. pestis strains and confirm that it results from the inhibition of SPase. We next investigated the origins of this unique arylomycin sensitivity and found that it does not result from an increased affinity of the Y. pestis SPase for the antibiotic and that alterations to each component of the Y. pestis lipopolysaccharide-O antigen, core, and lipid A-make at most only a small contribution. Instead, the origins of the sensitivity can be traced to an increased dependence on SPase activity that results from high levels of protein secretion under physiological conditions. These results highlight the potential of targeting protein secretion in cases where there is a heavy reliance on this process and also have implications for the development of the arylomycins as an antibiotic with activity against Y. pestis and potentially other Gram-negative pathogens.
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36
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Jahanian-Najafabadi A, Soleimani M, Azadmanesh K, Mostafavi E, Majidzadeh-A K. Molecualr Cloning of the capsular antigen F1 of Yersinia pestis in pBAD/gIII plasmid. Res Pharm Sci 2015; 10:84-9. [PMID: 26430461 PMCID: PMC4578216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Yersinia pestis which is the causative agent of pneumonic plague and distributed in all continents has led to many deaths during the history. Because of its high mortality rate, it must be diagnosed and treated at the earliest time post infection and therefore, rapid diagnostic tests are required. In the present study, we cloned the coding sequence of F1 capsular antigen of the bacteria in the pBAD/gIII plasmid for later expression and purification of the protein to produce poly and monoclonal antibodies against this antigen, and subsequently to develop rapid and efficient diagnostics tools for Y. pestis infections.
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Affiliation(s)
- A. Jahanian-Najafabadi
- Department of Pharmaceutical Biotechnology, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, I.R. Iran
| | - M. Soleimani
- Tasinim Biotechnology Research Center, AJA University of Medical Sciences, Tehran, I.R. Iran
| | - K. Azadmanesh
- Department of Virology, Pasteur Institute of Iran, Tehran, I.R. Iran
| | - E. Mostafavi
- Department of Epidemiology, Pasteur Institute of Iran, Tehran, I.R. Iran
| | - K. Majidzadeh-A
- Tasinim Biotechnology Research Center, AJA University of Medical Sciences, Tehran, I.R. Iran,Corresponding author: K. Majidzadeh-A Tel: 0098 21 88337928, Fax: 0098 21 88337928
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Merritt PM, Nero T, Bohman L, Felek S, Krukonis ES, Marketon MM. Yersinia pestis targets neutrophils via complement receptor 3. Cell Microbiol 2014; 17:666-87. [PMID: 25359083 DOI: 10.1111/cmi.12391] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2014] [Revised: 10/18/2014] [Accepted: 10/28/2014] [Indexed: 01/20/2023]
Abstract
Yersinia species display a tropism for lymphoid tissues during infection, and the bacteria select innate immune cells for delivery of cytotoxic effectors by the type III secretion system. Yet, the mechanism for target cell selection remains a mystery. Here we investigate the interaction of Yersinia pestis with murine splenocytes to identify factors that participate in the targeting process. We find that interactions with primary immune cells rely on multiple factors. First, the bacterial adhesin Ail is required for efficient targeting of neutrophils in vivo. However, Ail does not appear to directly mediate binding to a specific cell type. Instead, we find that host serum factors direct Y. pestis to specific innate immune cells, particularly neutrophils. Importantly, specificity towards neutrophils was increased in the absence of bacterial adhesins because of reduced targeting of other cell types, but this phenotype was only visible in the presence of mouse serum. Addition of antibodies against complement receptor 3 and CD14 blocked target cell selection, suggesting that a combination of host factors participate in steering bacteria towards neutrophils during plague infection.
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Affiliation(s)
- Peter M Merritt
- Department of Biology, Indiana University, Bloomington, IN, USA
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38
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Mouammine A, Lanois A, Pagès S, Lafay B, Molle V, Canova M, Girard PA, Duvic B, Givaudan A, Gaudriault S. Ail and PagC-related proteins in the entomopathogenic bacteria of Photorhabdus genus. PLoS One 2014; 9:e110060. [PMID: 25333642 PMCID: PMC4198210 DOI: 10.1371/journal.pone.0110060] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 09/07/2014] [Indexed: 01/14/2023] Open
Abstract
Among pathogenic Enterobacteriaceae, the proteins of the Ail/OmpX/PagC family form a steadily growing family of outer membrane proteins with diverse biological properties, potentially involved in virulence such as human serum resistance, adhesion and entry into eukaryotic culture cells. We studied the proteins Ail/OmpX/PagC in the bacterial Photorhabdus genus. The Photorhabdus bacteria form symbiotic complexes with nematodes of Heterorhabditis species, associations which are pathogenic to insect larvae. Our phylogenetic analysis indicated that in Photorhabdus asymbiotica and Photorhabdus luminescens only Ail and PagC proteins are encoded. The genomic analysis revealed that the Photorhabdus ail and pagC genes were present in a unique copy, except two ail paralogs from P. luminescens. These genes, referred to as ail1Pl and ail2Pl, probably resulted from a recent tandem duplication. Surprisingly, only ail1Pl expression was directly controlled by PhoPQ and low external Mg2+ conditions. In P. luminescens, the magnesium-sensing two-component regulatory system PhoPQ regulates the outer membrane barrier and is required for pathogenicity against insects. In order to characterize Ail functions in Photorhabdus, we showed that only ail2Pl and pagCPl had the ability, when expressed into Escherichia coli, to confer resistance to complement in human serum. However no effect in resistance to antimicrobial peptides was found. Thus, the role of Ail and PagC proteins in Photorhabdus life cycle is discussed.
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Affiliation(s)
- Annabelle Mouammine
- INRA, UMR Diversité, Génomes et Interactions Microorganismes-Insectes (DGIMI), Montpellier, France
- Université Montpellier 2, UMR Diversité, Génomes et Interactions Microorganismes-Insectes (DGIMI), Montpellier, France
| | - Anne Lanois
- INRA, UMR Diversité, Génomes et Interactions Microorganismes-Insectes (DGIMI), Montpellier, France
- Université Montpellier 2, UMR Diversité, Génomes et Interactions Microorganismes-Insectes (DGIMI), Montpellier, France
| | - Sylvie Pagès
- INRA, UMR Diversité, Génomes et Interactions Microorganismes-Insectes (DGIMI), Montpellier, France
- Université Montpellier 2, UMR Diversité, Génomes et Interactions Microorganismes-Insectes (DGIMI), Montpellier, France
| | - Bénédicte Lafay
- Université de Lyon, Écully, France
- CNRS, UMR5005 - Laboratoire Ampère, École Centrale de Lyon, Écully, France
| | - Virginie Molle
- Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, Universités de Montpellier 2 et 1, CNRS, UMR 5235, Montpellier, France
| | - Marc Canova
- Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, Universités de Montpellier 2 et 1, CNRS, UMR 5235, Montpellier, France
| | - Pierre-Alain Girard
- INRA, UMR Diversité, Génomes et Interactions Microorganismes-Insectes (DGIMI), Montpellier, France
- Université Montpellier 2, UMR Diversité, Génomes et Interactions Microorganismes-Insectes (DGIMI), Montpellier, France
| | - Bernard Duvic
- INRA, UMR Diversité, Génomes et Interactions Microorganismes-Insectes (DGIMI), Montpellier, France
- Université Montpellier 2, UMR Diversité, Génomes et Interactions Microorganismes-Insectes (DGIMI), Montpellier, France
| | - Alain Givaudan
- INRA, UMR Diversité, Génomes et Interactions Microorganismes-Insectes (DGIMI), Montpellier, France
- Université Montpellier 2, UMR Diversité, Génomes et Interactions Microorganismes-Insectes (DGIMI), Montpellier, France
| | - Sophie Gaudriault
- INRA, UMR Diversité, Génomes et Interactions Microorganismes-Insectes (DGIMI), Montpellier, France
- Université Montpellier 2, UMR Diversité, Génomes et Interactions Microorganismes-Insectes (DGIMI), Montpellier, France
- * E-mail:
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Differential contribution of tryptophans to the folding and stability of the attachment invasion locus transmembrane β-barrel from Yersinia pestis. Sci Rep 2014; 4:6508. [PMID: 25266561 PMCID: PMC4179465 DOI: 10.1038/srep06508] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 09/15/2014] [Indexed: 11/08/2022] Open
Abstract
Attachment invasion locus (Ail) protein of Yersinia pestis is a crucial outer membrane protein for host invasion and determines bacterial survival within the host. Despite its importance in pathogenicity, surprisingly little is known on Ail biophysical properties. We investigate the contribution of micelle concentrations and interface tryptophans on the Ail β-barrel refolding and unfolding processes. Our results reveal that barrel folding is surprisingly independent of micelle amounts, but proceeds through an on-pathway intermediate that requires the interface W42 for cooperative barrel refolding. On the contrary, the unfolding event is strongly controlled by absolute micelle concentrations. We find that upon Trp → Phe substitution, protein stabilities follow the order W149F>WT>W42F for the refolding, and W42F>WT>W149F for unfolding. W42 confers cooperativity in barrel folding, and W149 clamps the post-folded barrel structure to its micelle environment. Our analyses reveal, for the first time, that interface tryptophan mutation can indeed render greater β-barrel stability. Furthermore, hysteresis in Ail stems from differential barrel-detergent interaction strengths in a micelle concentration-dependent manner, largely mediated by W149. The kinetically stabilized Ail β-barrel has strategically positioned tryptophans to balance efficient refolding and subsequent β-barrel stability, and may be evolutionarily chosen for optimal functioning of Ail during Yersinia pathogenesis.
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Tang F, Saier MH. Transport proteins promoting Escherichia coli pathogenesis. Microb Pathog 2014; 71-72:41-55. [PMID: 24747185 DOI: 10.1016/j.micpath.2014.03.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Revised: 03/19/2014] [Accepted: 03/20/2014] [Indexed: 12/26/2022]
Abstract
Escherichia coli is a genetically diverse species infecting hundreds of millions of people worldwide annually. We examined seven well-characterized E. coli pathogens causing urinary tract infections, gastroenteritis, pyelonephritis and haemorrhagic colitis. Their transport proteins were identified and compared with each other and a non-pathogenic E. coli K12 strain to identify transport proteins related to pathogenesis. Each pathogen possesses a unique set of protein secretion systems for export to the cell surface or for injecting effector proteins into host cells. Pathogens have increased numbers of iron siderophore receptors and ABC iron uptake transporters, but the numbers and types of low-affinity secondary iron carriers were uniform in all strains. The presence of outer membrane iron complex receptors and high-affinity ABC iron uptake systems correlated, suggesting co-evolution. Each pathovar encodes a different set of pore-forming toxins and virulence-related outer membrane proteins lacking in K12. Intracellular pathogens proved to have a characteristically distinctive set of nutrient uptake porters, different from those of extracellular pathogens. The results presented in this report provide information about transport systems relevant to various types of E. coli pathogenesis that can be exploited in future basic and applied studies.
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Affiliation(s)
- Fengyi Tang
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, USA.
| | - Milton H Saier
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, USA.
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41
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Ho DK, Skurnik M, Blom AM, Meri S. Yersinia pestis Ail recruitment of C4b-binding protein leads to factor I-mediated inactivation of covalently and noncovalently bound C4b. Eur J Immunol 2014; 44:742-51. [PMID: 24760758 DOI: 10.1002/eji.201343552] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 10/10/2013] [Accepted: 11/25/2013] [Indexed: 12/14/2022]
Abstract
The outer membrane protein Ail of Yersinia pestis mediates several virulence functions, including serum resistance. Here, we demonstrate that Ail binds C4b-binding protein (C4BP), the primary fluid-phase regulator of the classical and lectin pathways. Non-covalent binding of C4 and C4b to Ail was also observed. C4BP bound to Ail can act as a cofactor to the serine protease factor I (fI) in the cleavage of fluid-phase C4b. Employing a panel of C4BP alpha-chain mutants, we observed that the absence of complement control protein domain 6 and 8 reduced binding to Ail. Immunoblot analysis of normal human serum (NHS)-treated bacteria revealed minimal C4b alpha'-chain complexes with bacterial outer membrane targets. Addition of the anti-C4BP monoclonal antibody MK104 to NHS restored C4b-alpha' chain target complexes, suggesting that C4b binds covalently to targets on the Y. pestis surface. C4b bound to Ail noncovalently was also cleaved in a C4BP and fI-dependent manner, leaving the C4c fragment bound to Ail. MK104 also prevented the cleavage of noncovalently bound C4b. Collectively, these data suggest that when C4BP is bound to Ail, fI can cleave and inactivate C4b that has bound covalently to bacterial surface structures as well as C4b bound noncovalently to Ail.
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Affiliation(s)
- Derek K Ho
- Immunobiology Program, Department of Bacteriology and Immunology, Haartman Institute, University of Helsinki, Helsinki, Finland
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Tsang TM, Wiese JS, Felek S, Kronshage M, Krukonis ES. Ail proteins of Yersinia pestis and Y. pseudotuberculosis have different cell binding and invasion activities. PLoS One 2013; 8:e83621. [PMID: 24386237 PMCID: PMC3873954 DOI: 10.1371/journal.pone.0083621] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Accepted: 11/14/2013] [Indexed: 11/18/2022] Open
Abstract
The Yersinia pestis adhesin Ail mediates host cell binding and facilitates delivery of cytotoxic Yop proteins. Ail from Y. pestis and Y. pseudotuberculosis is identical except for one or two amino acids at positions 43 and 126 depending on the Y. pseudotuberculosis strain. Ail from Y. pseudotuberculosis strain YPIII has been reported to lack host cell binding ability, thus we sought to determine which amino acid difference(s) are responsible for the difference in cell adhesion. Y. pseudotuberculosis YPIII Ail expressed in Escherichia coli bound host cells, albeit at ~50% the capacity of Y. pestis Ail. Y. pestis Ail single mutants, Ail-E43D and Ail-F126V, both have decreased adhesion and invasion in E. coli when compared to wild-type Y. pestis Ail. Y. pseudotuberculosis YPIII Ail also had decreased binding to the Ail substrate fibronectin, relative to Y. pestis Ail in E. coli. When expressed in Y. pestis, there was a 30-50% decrease in adhesion and invasion depending on the substitution. Ail-mediated Yop delivery by both Y. pestis Ail and Y. pseudotuberculosis Ail were similar when expressed in Y. pestis, with only Ail-F126V giving a statistically significant reduction in Yop delivery of 25%. In contrast to results in E. coli and Y. pestis, expression of Ail in Y. pseudotuberculosis led to no measurable adhesion or invasion, suggesting the longer LPS of Y. pseudotuberculosis interferes with Ail cell-binding activity. Thus, host context affects the binding activities of Ail and both Y. pestis and Y. pseudotuberculosis Ail can mediate cell binding, cell invasion and facilitate Yop delivery.
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Affiliation(s)
- Tiffany M. Tsang
- Department of Microbiology and Immunology, University of Michigan School of Medicine Ann Arbor, Michigan, United States of America
| | - Jeffrey S. Wiese
- Department of Biomedical and Diagnostic Sciences, University of Detroit Mercy School of Dentistry, Detroit, Michigan, United States of America
| | - Suleyman Felek
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, Michigan, United States of America
| | - Malte Kronshage
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, Michigan, United States of America
| | - Eric S. Krukonis
- Department of Microbiology and Immunology, University of Michigan School of Medicine Ann Arbor, Michigan, United States of America
- Department of Biomedical and Diagnostic Sciences, University of Detroit Mercy School of Dentistry, Detroit, Michigan, United States of America
- * E-mail:
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Paczosa MK, Fisher ML, Maldonado-Arocho FJ, Mecsas J. Yersinia pseudotuberculosis uses Ail and YadA to circumvent neutrophils by directing Yop translocation during lung infection. Cell Microbiol 2013; 16:247-68. [PMID: 24119087 DOI: 10.1111/cmi.12219] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Revised: 09/03/2013] [Accepted: 09/19/2013] [Indexed: 12/14/2022]
Abstract
A Yersinia pseudotuberculosis (Yptb) murine model of lung infection was previously developed using the serotype III IP2666NdeI strain, which robustly colonized lungs but only sporadically disseminated to the spleen and liver. We demonstrate here that a serotype Ib Yptb strain, IP32953, colonizes the lungs at higher levels and disseminates more efficiently to the spleen and liver compared with IP2666NdeI . The role of adhesins was investigated during IP32953 lung infection by constructing isogenic Δail, Δinv, ΔpsaE and ΔyadA mutants. An IP32953ΔailΔyadA mutant initially colonized but failed to persist in the lungs and disseminate to the spleen and liver. Yptb expressing these adhesins selectively bound to and targeted neutrophils for translocation of Yops. This selective targeting was critical for virulence because persistence of the ΔailΔyadA mutant was restored following intranasal infection of neutropenic mice. Furthermore, Ail and YadA prevented killing by complement-mediated mechanisms during dissemination to and/or growth in the spleen and liver, but not in the lungs. Combined, these results demonstratethat Ail and YadA are critical, redundant virulence factors during lung infection, because they thwart neutrophils by directing Yop-translocation specifically into these cells.
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Affiliation(s)
- Michelle K Paczosa
- Graduate Program in Immunology, MERGE-ID Track, Sackler School of Biomedical Sciences, Tufts University, Boston, MA, USA
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Demarcating SurA activities required for outer membrane targeting of Yersinia pseudotuberculosis adhesins. Infect Immun 2013; 81:2296-308. [PMID: 23589578 DOI: 10.1128/iai.01208-12] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
SurA is a periplasmic protein folding factor involved in chaperoning and trafficking of outer membrane proteins across the Gram-negative bacterial periplasm. In addition, SurA also possesses peptidyl-prolyl cis/trans isomerase activity. We have previously reported that in enteropathogenic Yersinia pseudotuberculosis, SurA is needed for bacterial virulence and envelope integrity. In this study, we investigated the role of SurA in the assembly of important Yersinia adhesins. Using genetic mutation, biochemical characterization, and an in vitro-based bacterial host cell association assay, we confirmed that surface localization of the invasin adhesin is dependent on SurA. As a surA deletion also has some impact on the levels of individual components of the BAM complex in the Yersinia outer membrane, abolished invasin surface assembly could reflect both a direct loss of SurA-dependent periplasmic targeting and a potentially compromised BAM complex assembly platform in the outer membrane. To various degrees, the assembly of two other adhesins, Ail and the pH 6 antigen fibrillum PsaA, also depends on SurA. Consequently, loss of SurA leads to a dramatic reduction in Yersinia attachment to eukaryotic host cells. Genetic complementation of surA deletion mutants indicated a prominent role for SurA chaperone function in outer membrane protein assembly. Significantly, the N terminus of SurA contributed most of this SurA chaperone function. Despite a dominant chaperoning role, it was also evident that SurA isomerization activity did make a modest contribution to this assembly process.
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Mikula KM, Kolodziejczyk R, Goldman A. Yersinia infection tools-characterization of structure and function of adhesins. Front Cell Infect Microbiol 2013; 2:169. [PMID: 23316485 PMCID: PMC3539135 DOI: 10.3389/fcimb.2012.00169] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Accepted: 12/13/2012] [Indexed: 12/16/2022] Open
Abstract
Among the seventeen species of the Gram-negative genus Yersinia, three have been shown to be virulent and pathogenic to humans and animals-Y. enterocolitica, Y. pseudotuberculosis, and Y. pestis. In order to be so, they are armoured with various factors that help them adhere to tissues and organelles, cross the cellular barrier and escape the immune system during host invasion. The group of proteins that mediate pathogen-host interactions constitute adhesins. Invasin, Ail, YadA, YadB, YadC, Pla, and pH 6 antigen belong to the most prominent and best-known Yersinia adhesins. They act at different times and stages of infection complementing each other by their ability to bind a variety of host molecules such as collagen, fibronectin, laminin, β1 integrins, and complement regulators. All the proteins are anchored in the bacterial outer membrane (OM), often forming rod-like or fimbrial-like structures that protrude to the extracellular milieu. Structural studies have shown that the anchor region forms a β-barrel composed of 8, 10, or 12 antiparallel β-strands. Depending on the protein, the extracellular part can be composed of several domains belonging to the immunoglobulin fold superfamily, or form a coiled-coil structure with globular head domain at the end, or just constitute several loops connecting individual β-strands in the β-barrel. Those extracellular regions define the activity of each adhesin. This review focuses on the structure and function of these important molecules, and their role in pathogenesis.
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Affiliation(s)
- Kornelia M Mikula
- Macromolecular X-Ray Crystallography Group, Structural Biology and Biophysics, Institute of Biotechnology, University of Helsinki Helsinki, Finland ; The National Doctoral Program in Informational and Structural Biology, Åbo Academy Turku, Finland
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